By the mid-1950s Sir William Lyons began to realise that while he had an excellent share of the large saloon market, first with the Mk VII and later the Mk VIII and IX. The sports car market was also looking good after a run of victories at Le Mans, demand for the current XK 140 was outstripping supply! But there was something missing. Demand for a mid-sized 'compact' Jaguar model was growing and competitors were cashing in on this market segment while Jaguar was not.

The need for a smaller, cheaper high-volume model would be satisfied through the usual Jaguar method of using existing components such as the existing XK engine in 2.4 ltr, steering, suspension and Moss gearbox while bringing some new ideas to the mix. The compact saloon would be of monocoque construction without a separate chassis and later incorporate 4-wheel disc brakes.

The new '2.4 Saloon' (later became known as the Mk 1) was a luxurious car with frontal styling taken from the XK-140 and also displayed its own sensual curves. The interior was finished to the usual high Jaguar standard. However; in the interests of strength the window pillars were rather thick and gave the side view of the car a somewhat heavy appearance. Also; the narrow rear axle width caused high speed handling to be tricky at times. Nevertheless; when in 1957 the car was available with the 3.4 ltr engine and disc brakes it became a 120 m.p.h. motor car and was the favourite of rally and racing drivers alike.

When in 1959 the car was updated as the Mk 2 with more refined styling and available in 3.8 ltr form Jaguar created one of its most famous and desirable models. Gone were the thick pillars and narrow rear end. The interior was even more attractive and the driving experience made more exciting, the 3.8 Mk 2 was the fastest production saloon car of its time! Like the Mk 1, the Mk 2 became a standout competition car in every country where it was raced. In Australia drivers like Bob Jane and Ron Hodgson won many Touring Car races at the wheel of modified 3.8 Mk 2 cars.

After the Daimler Company was acquired by Jaguar a new Daimler saloon based on the Mk 2 was released in 1962. It used the 2.5 ltr V8 which proved to be just as refined as the XK power unit. The Daimler was aimed at a different more sedate customer and proved to be very popular. By 1967 Jaguar decided to re-badge the 2.4 and 3.4 Mk2 models as the 240 340 and also the Daimler 250 saloon. The 3.8 was dropped from this range but could still be had in the 3.8S or S Type as it was better known. By 1969 production of the 240, 340 and Daimler had ceased. While the Mk 1 is an acquired taste the Mk 2 in 3.8 manual with overdrive is probably (after the E-Type) the most popular classic Jaguar to own.

During the early 1960s the new large saloon known as the Mk X (later 420G) was not selling well. Sir William thought that he needed a model more luxurious than the Mk 2 and of smaller dimensions than the Mk X. This new model would be the 3.4 and 3.8 'S Type'.

Using the Mk 2 as a basis he styled the front with slim bumpers and Mk X style indicators. The rear end styling was very much like the Mk X, long and with more boot space than the Mk 2. The roof line was also less curved to give better head room for rear passengers. Most importantly from a mechanical point of view the rear axle used the modern independent rear suspension which had been introduced with the E-Type. The S Type was available from 1963 to 1968. While derided by some the 3.4S and 3.8S are becoming more popular as time goes by and certainly have a superior ride and are almost as quick as a 3.8 Mk 2!

The final chapter of Jaguars classic compact models is the 420 model. Released in 1966 as an even more luxurious version of the S Type it is based on, the 420 received the 4.2 ltr XK engine and had a more harmonious front styling that echoed the current 420G and mated with the long rear end more successfully than the S Type design. The interior of the car is almost identical to the S Type but has a bit less wood on the door cappings and featured a padded black dash surround which was a sop to the emerging safety rules of the time.

Jaguar also made a Daimler version of this car known as the 'Sovereign', Unlike the earlier Daimler it used the same XK engine as the 420 but had the fluted Daimler grille and rear plinth which some say suits this design better than the Jaguar designs. By 1969 the 420 and Sovereign models were no longer in production. Both are excellent, useable classic cars to own in the present day.